4 sourced reports, with what to check before you buy. Each one links to the page it was reported on.
Costly or dangerous
WaterWall reflector error 7E/7C — reflector unable to move (documented by Samsung support)
The DW90F89T0UMTAA is a WaterWall model (confirmed in the service manual for the DW90F8 AA series, which lists model code DW90F89T0UMTAA). Samsung documents the 7E/7C error as the reflector being blocked, mispositioned, or misinstalled. The official fix is user-level (remove obstruction, reseat vane, power cycle), but if the reflector or its drive fails mechanically, the error recurs and requires service.
What to check. If this unit throws 7E/7C, first check for a blocked reflector (pot handle, large knife, ladle) and reseat the vane on the gray shuttle. If the error persists after clearing obstructions and power-cycling, the WaterWall drive assembly likely needs a service visit — this is the single most documented failure mode for this model family.
5C error code — drain pump problem (documented in model-specific manual FAQ)
The 5C error indicates a drain pump problem; the manual advises checking the pump cover and for jams. This is a documented failure mode for this exact model.
What to check. If 5C appears, first check the drain pump cover is correctly assembled and the pump isn't jammed (often food debris). If it persists, the drain pump itself may need replacement — a service visit.
Leak control error (LC) triggered by filter cap not seated — owner report on Samsung's own product page
The owner reports an LC (leak control) error triggered by the filter cap not being clicked in correctly, and says the unit then 'spirals' and cannot be made to work normally. The same reviewer also reported the first delivered unit wouldn't work once installed.
What to check. If an LC error appears, first check the filter cap is fully seated — this owner found a mis-seated cap triggered the leak sensor even with no actual leak. If the error persists after reseating, the leak sensor or control board may need service; this owner's unit never recovered.
These reports come from the pages linked under each item: owner forums, repair guides and workshops. They are not a diagnosis of any one unit, and a careful check of the one you are buying still applies.
Text from the Kriko Dishwashers catalog, version 0.1.2, under the CC-BY-SA-4.0 license.
